Difference between revisions of "LlIntegerToBase64"

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(example on how to make use of fewer than 6 Base64 chars)
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|notes=*Only the first 6 of the 8 characters returned are needed to decoded it back into an integer. The padding "==" can be safely removed for storage.
|notes=*Only the first 6 of the 8 characters returned are needed to decoded it back into an integer. The padding "==" can be safely removed for storage.
*"Big-endian" refers to the fact that the most significant, i.e. highest byte of the integer is processed first: the first characters in the returned Base64 string correspond to this byte, and the last characters correspond to the least significant byte.
**Combined with bit-shifting, removing characters from the Base64 string allows more efficient packing of small values. See [[llBase64ToInteger#Caveats|llBase64ToInteger caveats]] for specifics.
|cat1=Base64
|cat1=Base64
|cat2=Encoding
|cat2=Encoding

Latest revision as of 11:37, 11 October 2023

Summary

Function: string llIntegerToBase64( integer number );

Returns a string that is a Base64 big endian encode of number

• integer number

Examples

string ASCII7ToString(integer letter)
{
    if(letter >= 0x80 || letter < 0) return "";//Not valid ascii7 character
    return llBase64ToString(llIntegerToBase64(letter << 24));
}
// Packs a 24-bit unsigned integer value (0-16777215) to only 4 Base64 characters.
string Int24ToBase64(integer value)
{
    return llGetSubString(llIntegerToBase64(value<<8), 0, 3);
}
// unpacks a 4-character Base64 value to a 24-bit unsigned integer
integer Base64ToInt24(string value)
{
    return (llBase64ToInteger(value)>>8)&0xffffff; // Masking required to remove sign extension from bit-shifting
}
If you are looking for full Unicode translation, not just ASCII7 see: Combined_Library

Notes

  • Only the first 6 of the 8 characters returned are needed to decoded it back into an integer. The padding "==" can be safely removed for storage.
  • "Big-endian" refers to the fact that the most significant, i.e. highest byte of the integer is processed first: the first characters in the returned Base64 string correspond to this byte, and the last characters correspond to the least significant byte.
    • Combined with bit-shifting, removing characters from the Base64 string allows more efficient packing of small values. See llBase64ToInteger caveats for specifics.

See Also

Deep Notes

Search JIRA for related Issues

Signature

function string llIntegerToBase64( integer number );